


Day Twenty-Two

by FellQueen (Nikasha)



Series: Kinktober 2019 [21]
Category: Undertale (Video Game)
Genre: Alternate Universe - Swapfell (Undertale), Deepthroating, Fear Play, M/M, Shotgunning, Sibling Incest, Swapfell Papyrus (Undertale), Swapfell Sans (Undertale), fellswap red
Language: English
Status: Completed
Published: 2019-10-23
Updated: 2019-10-23
Packaged: 2020-12-28 22:14:15
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 1,092
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/21144065
Author URL: https://archiveofourown.org/users/Nikasha/pseuds/FellQueen
Summary: Day Twenty-TwoPrompt: Fear play/shotgunningPairing: Fellswapcest (FellswapGold!Papyrus/FellswapGold!Sans)





	Day Twenty-Two

**Author's Note:**

> This isn’t my usual pairing, but hopefully I wrote them okay.
> 
> I wound up picking both prompts. Fite me.

He could still taste the acrid sensation of fear in his mouth. It mixed with the sight of gold magic spilled across his brother’s bones. Sans had been momentarily struck helpless as the idiots beat on his brother, breaking him and spilling his blood across the ground, and Sans had frozen, horrified and confused by their gumption. Then Papyrus had looked at him, that calm look he got when he was being hurt, and everything clicked back into place.  
Sans had left behind several piles of dust and the survivors had scattered with serious wounds.  
Sans made Papyrus walk home. He hadn’t wanted to, stars he hadn’t, but he couldn’t carry him and Papyrus was too weak to shortcut. It had taken twice the amount of time as usual, Papyrus limping along slowly and occasionally crumpling while Sans berated him, panicked and utilizing the only tool he had to galvanize his brother into action.  
At home, Sans had ordered Papyrus to sit while he found a firstaid kit and some food, then set about healing what he could.  
He was shaken. Papyrus could have died. Gone, like a candle flame blown out in an instant. Leaving behind only darkness. Even as he healed, he could only mask the injuries and boost Papyrus’s meager HP. He didn’t have the skill, and Papyrus the strength, to actually heal the injuries.  
Sans stood in front of his brother who was sitting on the couch, countless emotions roiling inside him in a dangerous cocktail. Papyrus didn’t dare meet his gaze, he noticed, focused wholly on the floor with his head lowered. “Mutt,” he croaked out and the word was full of venom.  
Papyrus didn’t flinch or cower or even really react. It hurt. “Milord.”  
He wanted to hurt him, to punish him, for daring to get used as a hostage. Strip him down to a trembling pile of waste. But he also didn’t. He couldn’t see more of his brother’s blood spilled tonight. He just couldn’t.  
Sans cupped his jaw in his hands, lifting Papyrus’s face. The mutt looked somewhat surprised by the gentle gesture, blinking and examining Sans’s gaze.  
He could’ve died. They could’ve both died.  
Hit with an unexpected rush, Sans surged forward and kissed him, arms wrapping around his neck. Papyrus grunted, leaning back against the couch and gripping Sans’s waist. He didn’t pull away or fight Sans’s dominating kiss, wouldn’t dare, but Sans could practically taste his confusion.  
Sans tugged insistently at Papyrus’s clothes and he obligingly retreated to strip down completely, jacket and pants tossed aside carelessly. Sans would get onto him later.  
For now, he had a gloriously bare-bones skeleton before him, a glint to his eyelight as he kept his head low, watching Sans. Waiting.  
“Good boy,” Sans purred and kissed him again hungrily. Papyrus tightened his grip on Sans and turned, pulling Sans down to the couch and looming over him. He moved slowly, giving Sans time to protest. He didn’t.  
He did growl when Papyrus broke their kiss to kneel, tugging his shorts lower to free Sans’s glowing erection. The growl abated and he placed his hands on Papyrus’s skull as the taller took him in hand, then down his throat.  
If there was one thing Sans would never fault his brother for, it was his stupid blowjob skills. He could take a cock without a wince and had a long, dextrous tongue that was able to coil around his length. He wasn’t phased even as he swallowed.  
He did choke when Sans grabbed his skull and fucked into him, though. If Sans was nice, the mutt could probably avoid any discomfort at all. Too bad Sans wasn’t nice.  
Papyrus didn’t seem to mind. His sockets slid shut and an almost peaceful expression crossed his face as Sans groaned and thrust into his mouth.  
“You look good like this, mutt,” he panted. “Serving me.”  
Papyrus rumbled like he was pleased and Sans came undone. He pulled Papyrus tight to his pelvis and groaned as he spilled magic down his throat. Then quickly said, “Don’t swallow.”  
Papyrus paused in that exact action, surprise crossing his face again. He slid his mouth off of Sans’s dick and looked up at him in question.  
Sans answered him by leaning down and pressing their mouths together. He licked his magic off of Papyrus’s tongue, swallowing it down. It tasted strange and not nearly as pleasant as Papyrus’s. But he did see it had evoked a heady reaction from his partner. Despite his patient stillness, the mutt was glowing brightly and hard as a rock.  
He wanted it. He pushed his shorts away irritably and nudged Papyrus to lay on the floor on his back, sitting on his dick and making them both moan.  
“You almost died.” It was like Papyrus was pushing the words out of him. “Fuck, we almost died, we could have died—“  
“No,” Papyrus interrupted quickly. “I won’t let you die.”  
Sans laughed harshly as he started moving his hips, riding Papyrus roughly. “Let me? How would you stop them? They could shoot me through the window right now. They could sneak in and stab me in the night. They could steal you away again.” His soul pulsed painfully and he shuddered. “Fuck, mutt, you’re so...useless.”  
Papyrus growled, but didn’t move. “Yeah,” he agreed in a breath. “Can’t do anything right.”  
Sans’s eyelight flared. “We could fix it right now.” A blaster whirred behind him, charging up, the maw pointed at them both. Just one command and they both would go down in dust.  
Papyrus’s breath quickened, focusing on that blaster pointed at his master, his brother. He didn’t try to talk him down.  
“Fuck,” Sans whispered. “I can feel you...twitching.”  
Papyrus sucked in a breath and came abruptly, groaning. “Milord,” he gasped, thrusting up into him jerkily.  
Sans panted, high off the adrenaline. He tilted his head back slightly and brushed the jaw of his blaster. Too close. Too large. He could feel the power teeming in its marrow.  
He dismissed it.  
Papyrus rolled them, pinning Sans down and burying his face in his neck. He shook violently, hugging to him tightly.  
Sans pet Papyrus’s skull gently. “Shh, mutt.”  
“Almost lost you.” It was unclear whether he meant the blaster or earlier.  
“I know,” Sans murmured. He fingered the spiked collar so heavily imbued with his magic. So useless against the angry enemies. “You’re a good mutt.”  
Papyrus’s breath hitched. “Love you.”  
Sans stares at the ceiling and felt his empty soul shake. “I know.”

**Author's Note:**

> List used: https://twitter.com/idek_uggy/status/1178349575725174786?s=21
> 
> Tomorrow is pet play!


End file.
